Moistener for hectograph duplicators



De@ M, @Si H. GERLACH ErAL '2,577,886

MOISTENER FOR HECTOGRAPH DUPLICATORS Filed sept. 23, 194s EXC-TM Patented Dec. 11,1951

MOISTENER FOR HECTOGRAPH DUPLICATORS Hugo Gerlach and Egidio' Maria Benello, London, England, assignorsi'toBlock & Anderson Limited, London, Great Britain England, a corporation of Application September 23, 1948, Serial No. 505,684 In'Great Britain September 27., 1947 This invention relates to mechanisms for applying liquids to sheets of paper and the like, and

2 claims. (c1. 91-38) has for its object to provide certain improvements -in or modications of mechanisms for applying liquid to a sheet of the kind comprising a capillary pad arranged in contact with a liquid applying roller adapted to apply the liquid to a sheet passing between it and a further roller, the capillary pad being inclined downwardly away from the area of Contact with the liquid applying roller, ya

pad supporting tray embracing the lower part of the pad, means for supplying liquid to the pad, and a drainage outlet provided in the pad 4tray at or near the lowermost part of the tray to withdraw any surplus liquid from the tray, the liquid preferably being supplied to the capillary pad from a reservoir at a lower level by the actuation of a pump and the drainage outlet leading to a pipe discharging into the reservoir. An example of such a liquid applying mechanism is disclosed in application Ser. No. 655,760, filed May 20, 1946 by Hugo Gerlach, now Patent No. 2,533,572, issued December l2, 1950 and in the construction as described with reference to the drawing accompanying the said application, the liquid delivered by the pump passes into a concentric tube system comprising an inner tube with upwardly directed orifices and an outer tube fed by the liquid from the orifices in the inner tube and having downwardly directed orices through which the liquid is discharged onto the capillary pad. When used as a damping device for moistening the copy sheets which are to be brought into contact with the hectographic original or master sheet on a hectograph copying, machine, the applying roller E and the co-operating roller of the mechanism according to the said specification constitute a pair of feed rollers moistening and advancing the moistened copy sheet to the printing couple, consisting of a master drum and pressure roller. in the case of the mechanism according to the said application, the improvements according to the. present invention are particularly well adapted for use in such rotary hectographic copylng machines. y Y

According to the present invention, in a liquid applying mechanism of the kind set forth, including a spray tube extending across the capillary pad rthrough which tube the liquid is sprayed onto the pad, the spray tube is so mounted and arranged as to be rotatable about its own axis. This rotation enables the spray holes to be moved so as to vary their operative position or to be moved from their operative position-directed towards the pad into an inoperative position in which for instance they are readily accessible for cleaning. Where a concentric tube system is used with the finest holes in the outer tube, it is only necessary to rotate the outer tube for cleaning the ne holes as in general there will be little tendency for the larger holes in the inner tube to become clogged. However, if desired, the concentric tubes may be mounted as a unit and inner and outer tubes may be rotated simultaneously when it is desired to clean the holes in the outer tube.

' One embodiment of theliqud applying mechanism in the form of a damping device for a hectographic copying machine will now be described more fully by way of example with reference to vthe accompanying drawing, in which:

Figure 1 is a fragmentary side view of the machine, and

Figures 2 and 3 are enlarged detail views in two dilerent settings of the spray tube assembly.

In the drawing, I represents a side frame of the machine, on which the other components are mounted. The printing drum 2, which is provided in known manner with means for releasably securing a hectographic master sheet, co-operates with a pressure roller 3 to form the printing couple, The sheets on which copies are to be obtained are fed singly through the printing `couple and as each sheet is fed the surface con'- vanced. r'The solvent liquid is supplied to the 'roller 4 by means of a capillary pad 6, e. g. of felt,

which is mounted in a pad holder 1 and is inclined downwardly away from the roller 4. At its lower- 'most point, the pad holder I is provided with a drainage pipe 8 through which any surplus liquid is discharged into a collecting trough 9 from which the surplus liquid is returned to the reservoir II .by way of the connecting pipe I0. The liquid is sprayed on to the pad 6 from a spray tube assembly I2, I3 'extending across the machine approximately above the rear edge of the pad B. In the construction shown, the spray tube assembly comprises an outer spray tube I2 provided with a number of spray holes distributed over its length so as to give substantially uniform distribution of liquid along the length of the pad, viz. transversely of the machine. An inner tube I3 is provided with a smaller number of coarser holes and assists in the even distribution of the liquid 3 along the length of the outer tube I2. The liquid is supplied from the reservoir II to the inner tube I3 by means of a pump I5 (not shown in detail) arranged to make one stroke on each revolution of the drum I. The pump I is connected to the tube I3 by means ofa `flexible supply pipe 29.

According to the invention, the spray tube I 2 is provided at one end with a control arm I4 whereby the tube I2 can be rotated about its axis to vary the position of the spray holes. In the `crnluzudlment shown, it is assumed that the inner tube Il is stationarily mounted and gives a number of upwardly directed jets as indicated at 21 iin-.Figures 2 and 3. The jets 28 from the spray holes in the tube I2 may be directed at the lower edge of the felt 6 as in Figure 2 or at the `upper edge as shown in Figure 3, or intermediately. 'For cleanlng'purposes, the tube I2 is rotated until the holes are presented upwardly, so that any obstruction can readily be removed. Figure 2 shows the normal pperating position of -the jets 29 and Figure 3 shows the position for priming the felt pad, 5 to ensure that liquid is available at the upper edge a; .quickly as possible after starting to operate. The'setting of the spray tube can be indicated by the oo-operationof the arm I4 with a xed scale 25 and, if desired, provision may be made i'or re- `lesably securing the arm I4 in the desired setting, e. g. in the manner hereinafter described in relation to the lever 22. For a given pump delivery, the arrangement ailords the possibiiity also of varying the supply of liquid to the roller 4 `by adjustment of the direction of the jets 28 betweenthe limiting positions of Figures 2 and 3. The `more conventional procedure however is to supply the liquid during normal running to .the lower edge of the pad Ii as indicated in Figure 2 and to control the degree of moistening vby varying the delivery of the pump I5.

The pump I5 is operated once during each rotation `of the drum 2 by means of a cam I8 4cari-led .by the Adrum 2 and engaging one end of a lever I1 the other end of which engages a pocker I6 `aiialted to cause the pump I5 to per-form its delivery stroke. The return stroke is caused by -a `spring (not shown) in well known manner. delivery is varied by adjusting the stroke `of the pump and this is effected by limiting Ythe return stroke by the engagement with a cam of a pin I9 carried by the rocker I6. To enable .the cam ,20 to be positioned conveniently from the operators position (left hand -end of the machine in Figure l), a link 2| extends between the cam 20 and Va control lever 22 which can be latched in any one of a number of predetermined positions by means of a notched. quadrant 23. In Figure l, the lever 22 is shown in the position in which the pump I5 performs its maximum stroke to give the maximum delivery. If a constant pump delivery is desired, the cam 20 can kbe omitted and the lever 22connected directly 4 to the arm I4 by a link equivalent to link 2l, the adjustment of the lever 22 then determining the direction of the jets 28 without iniiuencing the total quantity of liquid delivered.

To enable a supply of liquid to be introduced. the reservoir Il is provided with a pivoted filler cap 24 which is shown in the open position in -Figure 1.

, applicator and having an upper end portion in surface contact therewith. liquid supply means including a spray member disposed above a lower end portion of the pad and having a longitudinal series .ot ports to direct liquid in jets thereunto for capillary transmission to the surface of the applicator, means supporting said spray member for movement relative to said pad, and means in operative 'connection with the spray member 'to -move it into .different positions of adjustment for selectively directing the jets of liquid onto the pad at its upper end and at different points between its ends `whereby to regulate the supply of liquid to the surface of the applicator.

2. Moistener apparatus for hectographlc duplicators comprising a rotary applicator, a capillary pad having a portion in surface contact therewith, liquid supply means including a dipensing tube disposed over the pad, a spray tube enveloping the dispensing tube in concentric spaced relation and having a longitudinal series of ports to direct liquid from the dispensing tube `in jets onto the pad for capillary transmission to the surface of the applicator, said spray tube being rotatable on its axis to vary the direction of its jet ports relative to the pad, and manual control means secured to an end of the spray tube whereby to rotate the tube for selective direction of its jet ports relative to the pad.

HUGO GERLACH. EGIDIO MARIA BENELLO.

REFERENCES CITED T'hev followingvreferences are of record in the file ofv this patent:

UNITED STATES PATENTS Number Name Date `1,851,538 Day et a1. Mar. 29, 1932 2,146,809 Flint Feb. 14, 1939 l 2,225,749 Marchev Dec. 24, 1940 2,299,967 'Denison Oct. 27, 1942 2,299,994 Kokay Oct. 27, 1942 2,360,648 Copeland et al Oct. 17, 1944 FOREIGN PATENTS Number Country Date Great Britain Sept. 21, 1948 

